The trick to onion soup is caramelizing the onions. The sweetness of the onions comes out when they are sautéed slowly until they are dark brown. This requires that you stand at the stove for an hour. Put on music and sing. Listen to an audio book. Or use my kitchen hack of browning the onions in a slow cooker, which is in the Options and Extras section of this recipe. This hack needs to be done the day before you need the caramelized onions because it takes 10 or more hours in the slow cooker, but you needn’t keep your eye on it while it does its magic.
3 lbs (1.4 k) onions (I like to use a mix of yellow and red ones)
3 tbsp (45 ml) olive oil
2 tbsp (28 g) sweet, unsalted butter
1 tsp (6 g) salt
A pinch or two of dried thyme
A splash of dry red wine
2 cloves garlic, minced
1 tbsp (15 ml) soy sauce or tamari
8 cups (1.9 l) vegetable stock
1 8-oz (237 ml) container heavy cream
Peel the onions, halve them and slice them thinly.
Heat the olive oil and the butter in a thick-bottomed soup pot.
Add the onions and salt and sauté over a medium heat, stirring often. This will take upwards of an hour.
Sauté until the onions are brown with some blackened bits.
Add minced garlic and sauté until the garlic is soft.
Add the wine and deglaze the pan by scraping up the lovely brown glazed bits from the bottom of the pan.
Take a pinch of two of thyme and rub it in your hands over the pot, letting it fall in. Give it a stir.
Add the vegetable broth and the soy sauce (or tamari)
Simmer the soup for about 20 to 30 minutes.
While the soup is simmering, whip the cream. Don’t add sugar or anything to it. Just whip it until it’s stiff enough to plop from a spoon and keep its shape.
Ladle the piping hot soup into bowls and plop a spoonful of whipped cream on top. The whipped cream will melt into the soup and add a depth of flavor.
Options and Extras:
- You can caramelize the onions in a slow cooker the day before you want to make this soup. It will take 10 to 12 hours. To do so, fill your slow cooker with sliced onions. (about 4 pounds of onions). Add 4 tablespoons of melted butter or olive oil and mix it up. Cook on low for 8 hours. If they look too liquid-y, set the lid of the cooker about an inch ajar for the last 2 hours. You can also add 1 tablespoon of brown sugar and 1 tablespoon of balsamic vinegar to further bring out the onions flavor. Continue cooking on low for 2 more hours.
- To make the soup with already caramelized onions, scrape them into a pot and start from when you add the garlic.